Friday 13th is the right day for the result of the Irish referendum on the Lisbon treaty to be announced, if the recent opinion polls are anything to go by. But what happens if the vote does reject the treaty?

The consequences of a putative British No to the Lisbon treaty have already been covered (read an analysis here) but not the consequences of an Irish No vote. I think these consequences would be rather different, because an Irish No would not be an expression of hostility to the EU as such but rather an expression of doubt about its pace and direction. The real meaning of a No vote lies in the motivation of the No campaigners and not only in the legal and institutional consequences of the treaty’s rejection. (This is why a British No vote would be such a threat to British membership of the EU.)

I don’t think that an Irish No would have particularly serious consequences for Ireland, but it would have serious consequences for the Irish and for the EU as a whole. By that, I mean that the threats of isolation and Ireland being sidelined in future EU developments are rather hollow. If there is a proposal for a future EU initiative on some aspect of economics, for example, it will be open to Ireland to choose whether or not to take part. The judgement of the other countries of the desirability of Irish participation will not be substantially affected by a No vote. If such a vote were the start of a longer-term isolationist policy trend within Ireland itself, then things might turn out to be different, but we cannot say for sure if that will transpire in practice.

In looking at the consequences for the EU as a whole, it is worth dividing the effect of the Lisbon treaty can be divided into two parts: improvements to the effectiveness of the EU institutions, and improvements to the standard of democracy. If the Lisbon treaty is rejected, what happens to those two parts?

Many of the proposals for effectiveness can be dealt with in other ways. A number of the institutional questions, such as representation regarding foreign affairs, can be addressed in some degree through intergovernmental decisions and changes to the working methods of the Commission and the Council. It would be preferable for these changes to be explicitly written into the treaties, and explicitly confirmed by the voters, but they will not all be lost. (This is what Mark Mardell is referring to in his blog here.)

But the democratic aspects will be much harder to resurrect. Many of these, such as strengthening the link between the European elections and the choice of Commission president, have been watered down in the current text since the Convention first proposed them, and it is hard to see how national governments will want to fight hard for them now (many of them actually think that proposals for more European democracy make their life harder rather than easier). At the very minimum, there is likely to be delay beyond the elections to the European Parliament to be held next June.

Failing to improve the democratic quality of the EU institutions at the same time as attempting to do more through them (there are many issues on the agenda where we need Europe to play an important role) may well end up making things worse rather than better. Rejecting the new treaty does not leave us with the status quo – nothing in the outside world is standing still – so an Irish No vote will weaken Europe and deny its citizens the voice they ought to have.